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#=========================================================================
# crt0.S : Entry point for RISC-V user programs
#=========================================================================
.section .text.libgloss.start
.global _start
.type _start, @function
_start:
# Initialize global pointer
.option push
.option norelax
1:auipc gp, %pcrel_hi(__global_pointer$)
addi gp, gp, %pcrel_lo(1b)
.option pop
# Clear the bss segment
la a0, metal_segment_bss_start
la a2, metal_segment_bss_end
sub a2, a2, a0
li a1, 0
call memset
# Copy data segment
la a0, metal_segment_data_target_start
la a1, metal_segment_data_source_start
la a2, metal_segment_data_target_end
sub a2, a2, a0
call memcpy
fence.i
# Copy itim segment
la a0, metal_segment_itim_target_start
la a1, metal_segment_itim_source_start
la a2, metal_segment_itim_target_end
sub a2, a2, a0
call memcpy
# Copy lim segment
la a0, metal_segment_lim_target_start
la a1, metal_segment_lim_source_start
la a2, metal_segment_lim_target_end
sub a2, a2, a0
call memcpy
la a0, __libc_fini_array # Register global termination functions
call atexit # to be called upon exit
call __libc_init_array # Run global initialization functions
li a0, 1 # a0 = argc = 1
la a1, argv # a1 = argv = {"libgloss", NULL}
la a2, envp # a2 = envp = NULL
call main
tail exit
.size _start, .-_start
.global _init
.type _init, @function
.global _fini
.type _fini, @function
_init:
_fini:
# These don't have to do anything since we use init_array/fini_array.
ret
.size _init, .-_init
.size _fini, .-_fini
/* This shim allows main() to be passed a set of arguments that can satisfy the
* requirements of the C API. */
.section .rodata.libgloss.start
.balign 8
argv:
.dc.a name
envp:
.dc.a 0
name:
.asciz "libgloss"
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